MADRID — Cannabidiol (CBD) extract may offer meaningful benefits for children and adolescents with autism spectrum disorder (ASD), improving social responsiveness and reducing disruptive behavior, results of a meta-analysis of three randomized, placebo-controlled trials suggested.

“Dysfunction in the endocannabinoid system, a regulatory network that modulates intercellular signaling, has been suggested as a potential contributor to ASD,” said study investigator Lara Cappelletti, MD, São Camilo University Center, University of São Paulo, São Paulo, Brazil. “By supplementing with CBD, balance may be restored to the system, leading to symptom relief,” she told Medscape Medical News.

The findings were presented on April 8 at the European Congress of Psychiatry (EPA) 2025.

Improved Social Response

The study included 276 children and adolescents with ASD. Most participants were male (78.3%) with a mean age of 10.5 years (range, 5-21 years). They received orally administered CBD extract containing minimal tetrahydrocannabinol (THC).

CBD concentrations ranged from 5 to 167 mg/mL, with CBD-to-THC ratios between 9:1 and 20:1. Dosages began at 1 mg/kg per day and were titrated up to 10 mg/kg per day.

The studies assessed social responsiveness, disruptive behavior, anxiety, and sleep quality using a range of validated tools, including the Social Responsiveness Scale, 2nd Edition; the PROMIS anxiety and sleep measures; the Home Situations Questionnaire-ASD; the Vineland Adaptive Behavior Scales, 3rd Edition; and the Adaptive Behavior Composite.

Additional assessment scales included the Autism Treatment Evaluation Checklist, the Childhood Autism Rating Scale, the Developmental Behavior Checklist 2, and the Clinical Global Impression–Global Improvement scale. Parental stress and sleep patterns were evaluated using the Autism Parent Stress Index and the Children’s Sleep Habits Questionnaire, respectively.

Results showed moderate improvements in social responsiveness compared with placebo (standard mean difference [SMD], −0.75) and “small yet notable” reductions in disruptive behavior (SMD, −0.36), said Cappelletti. There was no significant impact of CBD on anxiety or sleep quality, with no difference in adverse effects compared with placebo.

“The global population prevalence of ASD diagnosis amongst children and adolescents is growing, but many treatment pathways are not effective,” she concluded. “It is promising to see the effect of CBD cannabis extract on the study participants. However, there still needs to be considerable focus on further research with larger trials to clarify its efficacy and safety in managing ASD.”

Need for a Viable Treatment Option

Commenting on the findings for Medscape Medical News, EPA president Geert Dom, MD, PhD, professor of psychiatry at the University of Antwerp, Antwerp, Belgium, and medical director of the Multiversum Psychiatric Center in Boechout, Belgium, noted that ASD often presents significant challenges not only for the children and adolescents affected but also for their parents and the clinicians involved in their care.

“A large part of this frustration is down to finding a viable treatment option that works to reduce symptoms. It is with delight that we see the results of this meta-analysis, and we hope to see further research into this so we can move towards a solution to the unmet need within this community,” Dom said.

Cappelletti and Dom reported no relevant financial disclosures.

Kate Johnson is a Montreal-based journalist with more than 30 years of experience writing about all areas of medicine.